hybrid89

iTrader: (2)

Let me preface this by saying that I have been fighting this issue for a while (a few years) off an on. Everything I have done I have tried to do by the book and not cheat anything, but for the life of me I can't seem to get motor to run absolutely correct (and for CA smog non the less). I will try and give you guys any and all info that I can think off so I don't waste a lot of time with the basic crap that most over look and are not willing to put in time to do right. I have built many engines (specifically Honda) over the last 15 years and of course this one is stumping me. Anyhow here goes.....

92 Civic CX
ODB1 D15b vtec (P08) with matching non chipped P08 ECU
bottom end 100% stock.
top end has mild port match and polish and head milled .040
Y8 intake manifold port matched with b16 TB
only bolts ons at the moment are B&M adjustable FPR (set at 42 psi) / Fuel pressure gauge and a Skunk 2 adjustable cam gear. - I also have a Apexi VAFC, but doesn't even have any correction curves set until 2500+ RPM ---- AND YES that was tuned on a dyno (not the butt dyno), but with an Apexi 4-1 header and a AEM cold air intake (not currently in the setup).

I built this motor from the ground up about 5 years ago. Had a huge issue running lean and didn't realize that I had accidentally threw in 190cc injectors from a CX motor I had. Swapping to 240cc's solved a lot of my issues.

This is my main fight now - passing Smog. Failed again today with these numbers:

15MPH - RPM 1778 - %C02 14.7 - %02 0.0 - HC (PPM) MAX 108/ Measured 200 - C0% MAX .57 / Measured 0.27 - NO (PPM) MAX 835 /Measured 49 = Fail for HC
25MPH - RPM 1955 - %C02 14.8 - %02 0.0 - HC (PPM) MAX 73/ Measured 81 - C0% MAX .48 / Measured 0.22 - NO (PPM) MAX 542 /Measured 5 = Fail for HC

91 Octane
Timing at 13* BTDC
Cam Gear adjustable to +2 degrees advanced (get into this later)

Just replaced last weekend -
Bosch O2 sensor
Walker CA Carb Cat
NGK plus wires
NGK spark plugs (7 range - 1 step colder to hopefully help with ping/detonation)
New OEM air filter
New Cap and Rotor

Changed oil and filter the weekend before last after Seafoaming car to help with any carbon deposits on pistons (Sea Foamed intake only - not added to oil or gas)

Fuel filter was changed 6 months ago

I can hear the car ping and knock under load on the smog dyne (just barely and worse on the 15MPH than the 25 MPH). I can't retard the distributor any farther for smog purposes (even though I have room to move physically)
I assume this is causing the high HC due to misfire and unburnt fuel

Now the whole reason for the cam gear adjustment - Since building this motor, I could never get the ignition timing correct (physical adjustment) with the stock cam gear on. After reading through multiple forums and such, it dawned on me how much I took off the head when it was built (which is also not helping with the ping with our crappy 91 octane gas in CA)
So, when it went to my buddys dyno, we had the gear set at 3* advanced to get my ignition timing where it needed to be (adjustable within 14-18* BTDC). I have a very small window of going either way without issues = knocking pinging. I assume due to the higher CR with the milled head vs. gas I am running - the CR should be about 10.5:1 (from what I have calculated). I also understand that 2* advanced at the cam is a little much for a .040 mill to the head (should be more like 1* at tops, but the engine just doesn't seam to place nice with anything under 1.5* advanced at the cam (I get horrible smog numbers across the board HC/C0 and Nox) and I start loosing adjustment at the distributor to retard enough to get rid of the pinging.

So after much reading and working on this/trying combos this is where I am stuck: How the hell can I get my cam timing and my ignition timing to work as a team and run right/pass smog???

I know what most are going to say and this is to get a degree wheel and truly see where my cam sits etc. I don;t own one or really want to purchase one, plus it is a pain in the *** in the car. If I have to I will, but this is a lower budget D series mild build. Not a 600HP monster! But I also realized that after much reading, the issue with a half tooth error running a Y8 cam gear/ mini me setup vs PM3 (Z6) cam gear on certain cars (not my setup). But it got me thinking that maybe I was sold the wrong cam with the head (like a Y8 cam that is slotted different than a z6/15b cam). Not sure as I don't have one in front of me to compare, nor do I have a legit way to check cam lobes/duration/etc......but I don't see taking off half of the serviceable head limit would throw my mechanical timing this far off. I have a z6 cam gear and matches the OEM D15b gear exactly. Timing is 100% correct between crank and cam (checked a million times) with both gears installed to make sure. I just find it weird that my close to sweet spot is 4* advanced (4.5* being half tooth off if it was a gear /cam problem).

Besides this damn issue the car runs great. I built it using all OEM parts and don't cheap out on anything. This is my daily and has been a great car. The last few years I have slowly gotten rid of minor issues like erratic idle (the final fix to that was a new Evap purge solenoid), timing (cam gear adjustment) and such. But now that everything seems to be right at the spec it should be (except the cam degree and pinging), this has come to the forefront as my major hurdle I can't find a solution for.

Things I suspect may be an issue, but don't want to just "throw money" at parts. I want to know hat is going on with my setup:

Dying Fuel Pump - still OG form 92 (CX model - though that shouldn't be any different from any civic model from 92-95 in my knowledge) - My buddy that tuned it on the VAFC about a year ago found it funny that he could NEVER get the car to go rich no matter what he did - he was asking me If I had any issue with the fuel and from whatI can tell, there is none to my knowledge.

Faulty Ignition Coil - same as above, everything seems great, but maybe not getting enough spark - I have 2 extra lying around I could swap out. Also have a spare MSD 6al lying around from an old track car if needed...highly doubt I need to go that far. Stock ignition FTW

Possible Valve Lash out of spec now that my cam is 4* advanced???


Any help is greatly appreciated and I understand these types of situations are very hard to determine a fix for over the net, but I thought I would throw it out there to all that know more than I do. maybe someone has fought the good fight and found a solution or can offer a direction, cause I've been pulling my hair out over what I would consider something very simple for how many engine and cars I have worked on and built. Sometimes it takes an outside opinion to get the ball rolling in the right direction.

Matt

TomCat39

You said in the beginning you can't retard your ignition timing even though you have room on the dizzy.

Maybe you explained why but I think I may be slow and dense and am not sure why you can't retard a degree or two on the ignition timing to stop the pinging?

I read through the whole post to see why but must have missed it.

hybrid89

iTrader: (2)

I can retard the dizzy physically, but for CA smog I can only vary the dizzy +/- 3* from factory spec of 16*. So i can only technically go from 13*-19* before I fail the visual

Now my smog tech is cool and doesn't even check the timing, but to me something else is wrong and I should be able to properly time the car within spec.

MisereNoire

seriously, i would double check the mechanical timing, if it falls into spec and you still cannot find anything else off...use the mechanical timing as your base timing adjustment and match the ignition timing to the acceptable "visual range". This should allow for a greater "reach" on your usable ignition timing range, and perhaps even out the major ignition discrepancy. Although shifting that timing belt one tooth will likely move you just past that 3* usable limit anyway. anyhow, this shouldnt be a permanent fix, only to pass smog so you can save up to get that motor to someone to properly troubleshoot.

i suggest all this simply because...when i installed my ZC, it had been recently given a full tuneup/timing belt/etc. from the donor car. being a fool, i simply did a cursory visual inspection before dropping it in and driving it daily. It always ran lean-ish, and after i did my own plugs/wires/cap/ign. timing tuneup and brought the timing into the proper 16BTC, it started detonating/pinging at mid-high rpms. i then immediately tore the timing belt covers off and checked the mech timing...sure enough, it had been set one tooth off. i redid the timing belt/pump/tensioner with new components and set the mech properly, then reset ign properly...it now runs the proper AFR and the timing is dead on...no more pinging in ANY range, as it should be.

hybrid89

iTrader: (2)

I get what your saying I have have checked the mechanical timing over and over. I am going to give it one more go with the OEM cam gear on to make sure....

problem is, my timing now (on the dizzy) is about where it should be. 16* it almost straight up and down in the slot with about the same adjustment (retard/advance) either way. I would assume if I was off a whole tooth (9* difference), then it would be very skewed to one side or the other.

The other issue, is I want this to be correct and not just to "cheat" smog"......

TomCat39

The thing is, is it probably is correct. If the head has been milled at all or even using a thinner head gasket can up the compression enough to detonate under high load conditions. The easiest fix when this happens is a retard to the ignition timing until the detonation goes away.

The other fix is you switch to higher octane gas.

I know on my D15B7, all I did was change the head gasket (due to dropping a valve into the cylinder). I went from stock graphite thick gasket to the felpro MLS gasket that is much closer to the thickness of the 2 layer D16Y8 gasket. The compression ratio went from the typical 9.25 to the 9.78 and I started pinging in the top WOT range. I had to choose, either more expensive gas or a 2 degree retard (14* BTDC) ignition timing.

Money is tight so 87 octane and 14* BTDC ignition timing it has been.

hybrid89

iTrader: (2)

Ok went a tooth both ways today since I got off early. 1 way was way of a barely ran ( as suspected), going the other way, I could get it to run, but ran out of adjustment and could barely get to 15* BTDC at most....this was also with the stock cam gear so No adjustment involved. Like I said, I have gone over this many a time and I KNOW the mechanical timing is good. I also was pinging way worse with the last setup up....so back to where I was....hmmm..

hybrid89

iTrader: (2)

It may be where I am at I think. The one good thing I have is my civic is a CX, so timing on the hood says 12*, so in theory I could go as low as 9* BDTC before the smog tech should know anything is up. However that seams extreme. I am going to try 11* since I was trying 13* before and it ran great but NOT on the smog dyno. (slight ping on dyne causing misfire./ high HC). It just seams to me though that something is off to be that extreme from 16* being the standard on all these engines. An that is with my cam gear advanced 4*.....

I also notice a lag in power the more I retard the ignition..... which is the way it goes....any other ideas guys?

I am still thrown off by why my cam gear need so much advance for ahead that is NOT milled that crazy (compared to so setups)....maybe more fuel? bigger pump? injectors?

TomCat39

The head is milled 0.040 you said, that will cause a sginificant shift in mechanical timing. That means you need an adjustable cam gear to actually set mechanical timing correctly. The minime variance of the D16Y8 head on the D15B7 block I think is about a 0.040" difference if I remember my readings correctly. And that equated to half a tooth off or 4.75 degree difference.

hybrid89

iTrader: (2)

I have a Skunk2 adjustable cam gear on there and it is adjusted to 4* advanced (to help with the milled head and get my distributor with a workable range). Without it on (OEM cam gear or the gear set to 0), I can only retard my timing to 14.5*. I understand that for each .012 milled from the head I should advance the gear 1* which puts me at about 3* just for the milled head. I have ran that way for a while. But if I go to 4 degrees, I seem to have more adjustment in the ignition timing and it pings less. I don't want to go much further than that without clay.

When I first got the skunk2 gear, I thought It was the wrong one due to my timing issues, but have compared it extensively to the OEM gear and they are identical. This was added to my setup for the sole purpose of getting the mechanical timing correct.

I just threw the OEM gear on today for testing moving the belt a tooth each way. Like I said the mechanical timing is legit as it was before and I went back to my original setup (cam gear advanced 4* and the ignition timing set at 13* BTDC). This is the best road setup I have found that feels to have the most "power to ping" ratio that I can find. However, under smog dyne load, it still pings and I am failing because of it.

I just adjusted the ignition timing to 11* and took it up a steep hill by my house in 3rd gear at 1800 RPM and it barely started to ping at the top. Power feels smooth up top, but torque is lacking a bit. This is why I still think something is off.....

Also, I swapped my coil yesterday with a new one I had lying around from a buddy = no difference.

I am thinking new fuel pump, clean injectors (or replace). The other thing I have been researching is spark gap and the fact the D15b vtec calls for a long nose plug (NGK) which I am not running. I am going to try an order some up in 2 temp ranges.

It seams close but the numbers don't add up to me. Just frustrating....

TomCat39

Sorry forgot you already have the adjustable cam gear.

The other thing that happens that causes pinging is carbon buildup in the cylinders. You get enough build up it actually raises the Compression Ratio to cause pinging.

As far as I know, there is no real good way to clear that up without engine disassembly. If you have a bore scope you can get a decent look in your cylinders and see if it's got signs of heavy carbon.

You might be forced to run higher octane gas by default by the sounds.

You've gone over everything with a fine tooth comb multiple times. I suspect this is where you are at now.

tamboo

sh*t works! impressive!

TomCat39

That's the first solid demonstration I've seen of Seafoam. Couldn't figure out why no one used a bore scope prior to this.

Thank you for sharing.